In this condition the animals rapidly lose flesh, the appetite becomes irregular, the general condition gradually gets worse, and they die as a result of continued uro-septic fever or uræmic troubles.
The acute form takes a much more rapid course, with fever, more marked general disturbance, acceleration of pulse and breathing, the passage of turbid and sometimes purulent urine with a strong ammoniacal smell. Pyo-nephrosis is the most frequent and characteristic end. Ordinary chronic pyelo-nephritis may also occur in these cases, and the acute course may be determined simply by accidental ascending infections.
Diagnosis. During the early stages diagnosis is extremely difficult, unless a careful examination of the urine be made. Afterwards it becomes easy, the appearance of the urine and the indications furnished by rectal exploration being perfectly characteristic. In very exceptional cases there may be some doubt, as where the urine remains normal, in spite of hydro-nephrosis, or where there is old-standing hæmaturia or renal tuberculosis. In simple hæmaturia the lesions are confined to the bladder and ureters, the kidneys not being affected, and in renal tuberculosis the diagnosis can always be confirmed by the use of tuberculin.
Prognosis. The prognosis is extremely grave, for the lesions produced are irreparable, and, moreover, local intervention is impossible.
Treatment. There is no curative treatment. All that is possible is palliative treatment with the object of facilitating the function of the kidney and of disinfecting the urinary passages by administering antiseptic substances which are excreted by the kidney. It is not possible, however, to administer active drugs of this kind (e.g., combinations of carbolic acid). As the kidney acts badly it soon ceases to eliminate such substances, and the condition would not be improved, but aggravated.
Benzoate of soda in doses of 2 to 2½ drachms per day dissolved in diuretic liquids is the most useful drug, and sometimes holds the disease in check for a sufficient time to allow of the animals being fattened.
Treatment also comprises certain prophylactic precautions. As the infection which produces pyelo-nephritis originates in the genital tract, it is desirable to protect all animals in a receptive condition (those about to calve or having recently calved) from infection; hence, when the disease is detected in a cow-shed, the patients should be isolated, and the shed thoroughly disinfected.
SUPPURATIVE NEPHRITIS AND PERINEPHRITIS.
Suppuration of the kidney may occur under two conditions. In the majority of cases such suppuration occurs as a complication of pyelo-nephritis; less frequently it is the consequence of infection from within or infection of adjacent parts, leading to the formation of an abscess.
When it results from an ascending infection the kidney becomes swollen, congested and inflamed, and soon displays localised minute hæmorrhages. Pus then forms within the calices, in the large straight tubes, and diffuse suppuration invades all the uriniferous tubules. The enlarged kidney is yellowish, firm under the knife, and when sections are compressed pus exudes from the openings of the tubular canaliculi.